A corporate user and others manage data by using a storage control apparatus. The storage control apparatus stores user data to a redundant storage area based on a RAID (Redundant Array of Independent (or Inexpensive) Disks) in order to protect data.
The storage control apparatus is provided with a battery, and is configured to write dirty data that has been stored in only a cache memory to a storage apparatus by an electrical power from the battery in the case in which a power outage occurs (see Patent Literature 1). In a conventional art that is disclosed in the Patent Literature, as a remaining power level of a battery is less, a permissible amount of dirty data becomes less. In addition, in the case in which a remaining power level of a battery becomes equal to or less than a threshold value, a write back operation is switched to a write through operation.